The present invention relates to an operating device for a light-emitting means for determining an energy or power consumption and to a method for detecting information about an energy or power consumption of a light-emitting means. The operating device, according to the invention, for light-emitting means can be, for example, an electronic ballast for light-emitting means such as, e.g., gas discharge lamps or fluorescent tubes.
To implement illumination systems having a number of lamps, systems having a central control unit for controlling the operating characteristic of the lamps are used. In this context, characteristics such as operating comfort, ambience, functionality and energy saving and energy monitoring play an ever increasing role in the case of such illumination systems. The traditional electrical installation based on a simple wiring of light switches, dimmers and lighting-related loads can meet these requirements only inadequately. Modern operating devices which are linked in illumination systems can receive control commands for the operation of the corresponding light-emitting means or lamps via interfaces and then drive the light-emitting means in a correspondingly suitable manner. The control commands can then be conveyed both via a separate data or bus line or also as part of the PLC (Power Line Carrier) method via the power supply line. Furthermore, operating devices for light-emitting means are also known which have an interface for wirelessly receiving control commands.
Against this background, the lighting industry has defined a standard for digital communication between the individual components of an illumination system. This DALI (Digital Addressable Lighting Interface) standard is a protocol for controlling lighting-related operating devices such as, e.g., switched-mode power supplies, electronic ballasts or else electronic power dimmers. In this context, any operating device which has a DALI interface can be driven individually via DALI addresses. In comparison with the 1-10 volt interface frequently used previously, the DALI interface exhibits increased comfort for an intelligent light control in an illumination system. The DALI standard is an interface definition which is used especially for electronic ballasts for operating discharge lamps. DALI can also be linked as a cost-effective subsystem into a higher-level building management system via suitable converters.
A DALI light control system can be used as independent system for controlling illumination facilities. Furthermore, a DALI light control system can also be used as an independent subsystem in a pre-existing building management system. In this arrangement, a DALI system has a link to a higher-level building management system but is also operable without the building management system. In a further variant, the DALI system can be constructed as a pure subsystem in a building management system. In this type of application, the light system is not designed as a stand-alone solution. Commissioning of the light control system is in this case a component of the commissioning of the total building management system.
In principle, there are two possibilities for networking and operating a DALI light control system. As shown in FIG. 6, a control device 20 can control a number of operating devices 2 which are connected to one another via a bus 16. In this operating mode, the operating devices 2 connected are controlled by the control device 20, to which control panels or control units 40 such as, e.g., sensors, pushbuttons, dimmers or motion switches are connected. In this operating mode, the operating devices 2 forward information only on request by the control device 20. The entire handling is controlled by the control device 20.
As shown in FIG. 7, however, a number of control units 40 can also be connected to the interface line 16 and, therefore, communicate directly with the operating devices 2. In this arrangement, the control units 40 must observe corresponding “traffic rules” in the DALI standard in order to avoid data collisions and to allow the system to run correctly. In this operating mode, the installation is simpler and there is less wiring expenditure.
The control devices 20 establish the logical correlation between the control units 40 such as, e.g., sensors, operating elements and DALI operating devices 2. In principle, the control device can be an independent control device or else an interface module which obtains its instructions from a higher-level system such as, e.g., a building management system. Possible control devices 20 are also intelligent sensors or operating elements with integrated control device. As is shown in FIG. 6, sensors and operating elements 40 can be linked directly to the control device 20 via separate connections. By this means, commercially available components can then be used. In the variant as shown in FIG. 7, sensors and operating elements are linked to the control device 20 via the DALI lines 16. In this variant, no additional lines need to be run between sensors/operating elements and the control device.
In illumination systems, e.g. in buildings, the energy and power monitoring represents an ever more important aspect. In previous illumination systems comprising operating devices for light-emitting means, the energy consumption could hitherto only be estimated or determined via the measured total consumption. Estimation can take place by estimating the average dimming value or brightness value set and taking into consideration the corresponding power consumption of the installed operating devices. However, estimation of the energy consumption is rather cumbersome, on the one hand, and, on the other hand, also inaccurate since, for example, a real energy consumption of a light-emitting means can change in dependence on the duration of operation and thus in dependence on heating, when a dimming value is adjusted.